<?php
//dezend by http://www.yunlu99.com/ QQ:270656184
defined('BASEPATH') || exit('No direct script access allowed');
class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver
{
	/**
	 * Sub-driver
	 *
	 * @var	string
	 */
	public $subdriver = 'odbc';
	/**
	 * Database schema
	 *
	 * @var	string
	 */
	public $schema = 'public';
	/**
	 * Identifier escape character
	 *
	 * Must be empty for ODBC.
	 *
	 * @var	string
	 */
	protected $_escape_char = '';
	/**
	 * ESCAPE statement string
	 *
	 * @var	string
	 */
	protected $_like_escape_str = ' {escape \'%s\'} ';
	/**
	 * ORDER BY random keyword
	 *
	 * @var	array
	 */
	protected $_random_keyword = array('RND()', 'RND(%d)');

	public function __construct($params)
	{
		parent::__construct($params);

		if (empty($this->dsn)) {
			$this->dsn = 'odbc:';
			if (empty($this->hostname) && empty($this->HOSTNAME) && empty($this->port) && empty($this->PORT)) {
				if (isset($this->DSN)) {
					$this->dsn .= 'DSN=' . $this->DSN;
				}
				else if (!empty($this->database)) {
					$this->dsn .= 'DSN=' . $this->database;
				}

				return NULL;
			}

			$this->dsn .= 'DRIVER=' . (isset($this->DRIVER) ? '{' . $this->DRIVER . '}' : '{IBM DB2 ODBC DRIVER}') . ';';

			if (isset($this->DATABASE)) {
				$this->dsn .= 'DATABASE=' . $this->DATABASE . ';';
			}
			else if (!empty($this->database)) {
				$this->dsn .= 'DATABASE=' . $this->database . ';';
			}

			if (isset($this->HOSTNAME)) {
				$this->dsn .= 'HOSTNAME=' . $this->HOSTNAME . ';';
			}
			else {
				$this->dsn .= 'HOSTNAME=' . (empty($this->hostname) ? '127.0.0.1;' : $this->hostname . ';');
			}

			if (isset($this->PORT)) {
				$this->dsn .= 'PORT=' . $this->port . ';';
			}
			else if (!empty($this->port)) {
				$this->dsn .= ';PORT=' . $this->port . ';';
			}

			$this->dsn .= 'PROTOCOL=' . (isset($this->PROTOCOL) ? $this->PROTOCOL . ';' : 'TCPIP;');
		}
	}

	protected function _escape_str($str)
	{
		$this->display_error('db_unsupported_feature');
	}

	public function is_write_type($sql)
	{
		if (preg_match('#^(INSERT|UPDATE).*RETURNING\\s.+(\\,\\s?.+)*$#is', $sql)) {
			return false;
		}

		return parent::is_write_type($sql);
	}

	protected function _list_tables($prefix_limit = false)
	{
		$sql = 'SELECT table_name FROM information_schema.tables WHERE table_schema = \'' . $this->schema . '\'';
		if (($prefix_limit !== false) && ($this->dbprefix !== '')) {
			return $sql . ' AND table_name LIKE \'' . $this->escape_like_str($this->dbprefix) . '%\' ' . sprintf($this->_like_escape_str, $this->_like_escape_chr);
		}

		return $sql;
	}

	protected function _list_columns($table = '')
	{
		return 'SELECT column_name FROM information_schema.columns WHERE table_name = ' . $this->escape($table);
	}
}

?>
